Difference between revisions of "ICC profiles"
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[[Category:Graphics and DTP (English)]]
[[Category:Graphics and DTP (English)]]
Revision as of 06:19, 24 August 2010
- 1 Introduction
- 2 Profile Generation
- 3 Loading ICC Profiles
- 4 Additional Resources
As it pertains to general desktop use, an ICC profile is a binary file which contains precise data regarding the color attributes of an input, or output device.  Single, or multiple profiles can be applied across a system and its devices to produce consistent and repeatable results for graphic and document editing and publishing. ICC profiles are typically calibrated with a (tristimulus) colorimeter, or a spectrophotometer when absolute color accuracy is required.
 ICC Profile. Wikipedia, The Free Encyclopedia. Wikimedia Foundation, Inc. 6 July 2010. Web. 13 Aug. 2010. <http://en.wikipedia.org/wiki/ICC_profile>.
Profile generation on a Windows 7/Vista/XP, or Mac OS X system is one of the easiest and most widely recommended methods to obtain a ICC monitor profile. Since ICC color profiles are written to an open specification, they are compatible across operating systems. Transferring profiles from one OS to another can be used as a workaround for the lack of support for certain spectrophotometers, or colorimeters under Linux: one can simply produce a profile on a different OS and then use it in a Linux workflow. 2 Recommended colorimeters include the X-Rite i1Display 2 and the Spyder3 Pro. Note that the system on which the profile is generated must host the exact same video card and monitor for which the profile is to be used. Once generation of an ICC profile, or a series of profiles is complete on a Windows 7/Vista/XP system, copy the file(s) from the default path:
Mac OS X generally stores saved ICC profiles in one of two locations:
Once the appropriate .icc/.icm files have been copied, install the device profiles to your desired system. Common installation device profiles directories on Linux include:
/usr/share/color/icc /usr/local/share/color/icc /home/USER_NAME/.color/icc
2 Linux Color Management. Wikipedia, The Free Encyclopedia. Wikimedia Foundation, Inc. 23 Aug. 2010. Web. 22 Aug. 2010. <http://en.wikipedia.org/wiki/Linux_color_management>
LPROF ICC Profiler
Adjust the lighting in the room to what you will be using when working. Even if your screen is coated with an anti-reflective coating, you should avoid light falling directly on it. Let your monitor warm up for at least an hour for the image to get stabilized. If your calibration device has an ambient diffuser, adjust your room brightness to reach the recommended target lux point.
- Set the monitor contrast to maximum, or 100%.
- Next, display a pure black over entire screen by creating a small, black PNG image (all pixels have RGB = 0, 0, 0) and opening it up in a picture viewer that is capable of displaying an image in fullscreen mode without any controls.
- Reduce the vertical size of the monitor screen (not the PNG image displayed by a picture viewer but the whole of what's displayed on the screen) to 60% to 70% of the full height. What is revealed above and below the picture is called a non-scanned area, and since that are is not receiving any voltage, it is the blackest of black your monitor is capable of displaying.
- Locate the brightness control (usually a sun, circle with rays projecting from it's edges) and lower the value until the black image matches the non-scanned area.
As we said in the introduction, setting color temperature must occur at noon. If you only have fixed factory default color temperature, you don't really need to wait for the sunny day to come. Just set it to 6500K.
Place your monitor so that you can see outside the window and your screen at the same time. For this step, you also need to create a white square image (RGB = 255, 255, 255), roughly 10 by 10 centimeters (4 by 3 inches). Using the same Gwenview technique as with brightness/contrast, display the white square on a pure black background.
- First, prepare your eyes by staring at the outside world for a while. Let them adjust to the daylight viewing condition for a few minutes.
- Glance at the monitor, and the white square for a few second (it has to be short, because eyes will readjust quickly).
- If the square seems yellowish, you need higher color temperature, or if it has a blueish cast, the temperature needs to be lowered.
- Keep glancing, looking out the window, and adjusting the white temperature, until the square looks pure white
Take your time with the steps described above. It is essential to get it right.
Start lprof. You will be presented by a fairly large window with multiple tabs on the right.
- Click on the Monitor Profiler tab. Then click on the large Enter monitor values >> button.
- White point should be set to 6500K (daylight).
- Primaries should be set to either SMPTE RP145-1994, or EBU Tech.3213-E or P22, or whatever appropriate values for your monitor. If you come across correct values for your monitor, enter those by selecting User Defined from the drop-down. If in doubt, you may use P22 for all monitors with Trinitron CRTs (in this case, Trinitron is not related to Sony Trinitron mointors and TVs), and SMPTE RP145-1994 for other CRTs.
- Click the Set Gamma and Black Point button.
- You will now see a full-screen view of two charts with some controls at the bottom.
- Uncheck the Link channels check-box and adjust individual Red, Green, and Blue gamma by either moving the slider left or right, or by entering and changing values in the three boxes to the left. The goal is to make the chart on the left (the smaller square one) flat. When you are satisfied with how it looks, check the Link channels check-box and adjust the gamma again.
- When you are done, click OK. Click OK again.
When you are finished entering monitor values, you might want to enter some information about the monitor. This is not mandatory, but it is always nice to know what profile is for what.
- Click Profile identification button.
- Fill in the data.
- Click OK to finish.
After you are all done, click on the '...' button next to Output Profile File box. Enter the name of your profile: somemonitor.icc. Click Create Profile button, and you are done.
- Review the ArchWiki article Using LPROF to Profile Monitors for additional details on how to profile monitors.
- Review the official LPROF Main Help Window for details on how to profile additional devices, including printers and scanners.
- Review the official Argyll CMS documentation for details on how to profile selected devices.
Loading ICC Profiles
- xcalib is a lightweight monitor calibration loader which can load an ICC monitor profile to be shared across desktop applications. xcalib is part of the Arch User Repository (AUR)
Load profile Template:Filename in /usr/share/color/icc on display host:0 when X server starts
#!/bin/bash /usr/bin/xcalib -d :0 /usr/share/color/icc/P221W-sRGB.icc
JWM Template:Filename Example
Load profile Template:Filename in /usr/local/share/color/icc on display host:0 when JWM starts
Template:Filenamexcalib -d :0 /usr/local/share/color/icc/P221W-sRGB.iccTemplate:Filename
Load profile Template:Filename in /home/arch/.color/icc on display 0 when X server starts
#!/bin/bash /usr/bin/dispwin -d0 /home/arch/.color/icc/906w-Native.icc
JWM Template:Filename Example
Load Argyll calibration file Template:Filename in /usr/local/share/color/icc on display 1 when JWM starts
Template:Filenamedispwin -d1 /usr/local/share/color/icc/906w-Native.calTemplate:Filename